There is one sign already mentioned in other threads - ARCHIMEDES, the balloon-probe of the Mars Society already under development and testing via a prototype.

But the news from AdAstra Rockets and Excalibur Exploration shows that even more challenging and sophisticated exploration may be done privately - regarding the funds as far as at present can be mentioned.

Ad Astra Rocket Company, a Delaware corporation based in Houston, TX. and Excalibur Exploration Ltd., a British Company based in Douglas, Isle of Man, have signed an agreement grantingExcalibur Exploration Ltd. the right of first refusal to acquire VASIMRTM engines for space resource recovery.

So VASIMR doesn't cost so much that a private company like Excalibur Exploration couldn't buy it.

Next Ad Astra Rockets under www.adastrarocket.com explicitly mention that short trips to Mars would be possible.

So companies like Excalibur Exploration may be capable of doing interplanetary trips - for what purposes ever.

Of course "space ressource recovery" cautiously understood will mean recovery of satellites - but this doesn't mean yet that they couldn't apply VASIMR interplanetary. They might do scientific missions in service for ESA, NASA or others and getting paid for the service - at prices below the funds such agencies need.

Under www.adastrarocket.com I can't find no hints to a fission reactor. Ad Astra's VASIMR seems to consit of magnetic cells, an injector of neutral gas, the "RF booster" generating electromagnetic waves and a magnetic nozzle. They don't list a fission reactor nowhere.

yes I am aware of it but Ad Astzra also obviously. They seem to prefer solar power to power VASIMR. The creation of the plasma, the heating of the gas to make it a plasma seems to be done by electromagnetic waves, radio frequencies only - the drawings explicitly are showing antennas emitting them into the gas.

This reminds me to what I read about US-weapons applied during the Kosovo war. These weapons were bombs damaging nearly no building and no people - these bombs only emitted radio waves at therri explosions. These radio waves were of a frequency that heated the windings, wires, inductors of transformers which caused them to melt - so the transformer stations were damaged and the transmission of power was interrupted.

This might mean that gases can be heated a similar way and those weapons didn't apply no fuel of fission reactors. The transformer stations were much farther away from the mombs than the RF-antennas are from the gases in the drawings shown under www.adastrarocket.com .

They do show solar arrays in at least one drawing - may be that they have got the result that solar power can be sufficient. If they are correct and if I understand them correct private companies like Excalibur Exploration don't need a fission reactor in space - this would mean that they don't have to buy such a reactor. This in turn means that normal amounts of financial ressources are required - while a fission reactor would be a large or huge investment.